Siam is my favorite Thai restaurant in Urbana. I love their vegetarian options (even though I eat meat) - they make a mean mock duck and they are willing to substitute Seitan into just about any dish. I discovered the CRISPY pad thai about a year ago, and it's become my favorite dish (pad thai that's fried? what's not to love??).
The very best part about this restaurant is the fact that they deliver to Urbana residents EAST of Vine st. My only complaint about this place is the variable service (esp since they don't take reservations). I've been here for both dinner and lunch on several occasions and I have to say depending on which server you get, the service is either great or horrendous. beware...